ObjectiveTo analyze the clinical and dosimetric impacts on radiation pneumonitis (RP), and provides data for radiotherapy planning. MethodsWe reviewed 59 non-operative esophageal cancer patients who underwent radiotherapy from October 2010 to November 2012 to identify the correlation between the clinical and dosimetric parameters with acute radiation pneumonitis (ARP) and severe acute radiation pneumonitis (SARP) by t-Test, Chi-Square Test and logistic regression analysis. ResultsAmong the 59 patients, 33 (55.9%) developed ARP, in whom 9 (15.3%) developed SARP. Univariate analysis showed that lung infection during radiotherapy, mean lung dose (MLD), and dosimetric parameters are significantly correlated with RP. Multivariate analysis revealed lung infection during radiotherapy, MLD≥13 Gy, and V30≥13% were significantly correlated with the increasing risk RP. ConclusionLung infection during radiotherapy, MLD, and V30 are the influencing factors of RP, which should be seriously considered when formulating radiotherapy plan to avoid RP.
Objective To investigate the clinical factors and dosimetric parameters associated with grade≥2 radiation pneumonitis (RP) after thoracic radiotherapy in patients with locally advanced non-small cell lung cancer (NSCLC). Methods The clinical factors and dosimetric parameters in patients with locally advanced NSCLC who received thoracic radiotherapy at West China Hospital of Sichuan University between January 2016 and January 2018 were retrospectively analyzed. The potential factors associated with the occurrence of grade≥2 RP were analyzed with logistic regression analysis. Results A total of 104 patients were included, and the incidence rate of grade≥2 RP was 19.2%. Multivariate logistic regression analysis showed that the percentage of the heart volume that received more than 20 Gy (V20) [odds ratio (OR)=1.068, 95% confidence interval (CI) (1.004, 1.137), P=0.036], lung mean dose (Dmean) [OR=1.003, 95%CI (1.000, 1.006), P=0.031] and superior vena cava Dmean [OR=1.001, 95%CI (1.000, 1.001), P=0.041] were associated with grade≥2 RP. Receiver operating characteristic (ROC) curve analysis showed that the area under the ROC curve combined with heart V20, lung Dmean and superior vena cava Dmean to predict grade≥2 RP was 0.839 [95%CI (0.752, 0.926)]. In addition, the optimal critical values for heart V20, lung Dmean and superior vena cava Dmean to predict grade≥2 RP were 20%, 13 Gy and 38 Gy, respectively. Conclusions Heart V20, lung Dmean and superior vena cava Dmean are associated with grade≥2 RP after thoracic radiotherapy in patients with locally advanced NSCLC. In addition, taking heart V20<20%, lung Dmean<13 Gy and superior vena cava Dmean<38 Gy as normal organ dose limits may reduce the risk of grade≥2 RP after thoracic radiotherapy for locally advanced NSCLC patients.